MERIDIAN AUDIO ESL63 data

OUND

ESL-63

Extreme care

service

should be exercised

transformers

Read

all instructions

when

working

under

carefully

d*a

CAUTION

on the ESL 63 as contact with

signal

conditions can be fatal.

before

proceeding

with any work.

the secondarv

side of audio

30, St Peters

Telephone.

Road,

Ouad Electroacoustics

Huntingdon,

O4BO

5256/

Cambs,

Telex. 32348

Ltd.

PElB 7 DB,

OUAD

England.
G

OURD

ESL- 63 service

data

Contents
Description.
Protection
Fault
Testing
Test
Tone Burst
Service
Loudspeaker
Replacing
Repairing
Replacing
Modifications.
Component
Overiay Diagrams:

Components
Circuit Dragram
Circuit Diagram

Circuits

Finding

Equipment

Generator

Base

an

element . . .

a damaged

grille

cloth

Alternatives

Clamp/Detector
Clamp/Detector
EHT

Board
EHT Board
Coil

Board

List

ISS 1
ISS

dustcover

Board
Board

2

M1241 B ISS
Ml241
M12525 ISS
1,A12525
M12524

B

ISS

ISS
ISS

7
9,
2
3
6

1n

page

....,4

.....4

.,.'.5

.....7

.,...7
.. .8

. . .11
. .11

12

. . . .14

4r

tc
to

4^

IO

.

.17
.17

.

18

..18

19

. .20

.)a

. LZ

..23

OURD

ESL-63

description

service

data

The
diaphragm suspended
sequenta

that

of

ESL-63

Ouad

delay ines and the motion of the dlaphragm

from an idea source

protection

The audlo input ls fed to the audio transformers

such that signa
continuousy t can overheat and become
Sparks occurrlng
circuit wi I then cause temporary shutdown

period

oftme. The detector circuit will

is a full

range electrostalic loudspeaker

between two sets

circuits

{ed

with n

to the

the

loudspeaker

placed

loudspeaker

some 30 cms behind

elemenls is kept

aso operate if input

ot concentr c annu ar e ectrodes. Signa is fed to the electrodes v

via

damaged.

are detected

of the loudspeaker

doublet.

produces

the

a clamp

within sale limts.

by an antenna situated in the loudspeaker base. The detector

signal

lt

a sound

plane

circuit.

by short

is

consists of a

pressure paltern

the d

of

Input signa s

lf

circuiting the input for

applied

very light

aphragm.

in

excess of 40V are then clamped

however. the camp circuit runs

ln

the absence of

eectrically

which is an exact replica

pre-determined

a

AC

polarlsed

a

suppy vo1ts.

fault findi^g

OURD

ESL-63

service

data

Fault Find ng on a 63 may
important that

following

the

flä:li:L, finding under

transformers
Contact wlth the
from

the AC supply volts.
dlscharged
The flow diagram
equipment ayout shown in
Exit from
Shutdown
distorting and muffiing

FLOW DIAGRAM
Guidance
When dlsconnect ng the antenna
leads. The loudspeaker
baseplate after whlch
ot the clamp/detector
AUDIO
IS COMPLETED.
Atter this the

under signal

EHT

by short circuil

(Fig.

the diagram

reJers

to the

pul

for

SI]OULD NEVER BE

ng down

appropriate test

most easily be

notes

no circumstances

conditions as

path

should be avolded

lf the nature

po

ng

'1

reiers

)

wi I be at

state whch

effect on the

INSTRUCTIONS

shou d

lhe baseplate may

board.

to several

Fig. 2 is

one oI the diagnoses

the loudspeaker

be inverted

RE-APPL ED

cond tions should

di€noses

carried out

prior

read

be

this can be fatal,

of the work

(Fig.

nt A

exists when the

the following

5) to

tesls which

used as a bass

aud o.

cloth and removing

and stood on a firm clean surface. Remove

be fted

UNTIL WORK

by lollowing the

proceeding

to

w th any work.

shoutd contact be made

both when

earth, wlth AC supply volts

nstructions

out. The antenna shou d then be unsoldered from

be re-applied.

the ioudspeaker ls connected to

being undertaken necesstates

musl be carried out ln order to isolate faults. The

for all tests, uness olherwise

edch of

spark detector circuit s

wh

gr

should

BE]NG CARR ED OUT WITHIN THE LOUDSPEAKER

flow

diagram on

with the secondary

disconnected.

is

ch

c early defined below.

operating.

les

can be

followed.

be

found

Disconnect AC supply and audio

(Fig.

or

contact. the EHT

stated.

lt

mav be identfied

under service notes 2

12

the

1),

however il ls

side ot the

y

recent

screws securing the

disconnectedr?

should flrsl be

test

by ts

(a)(b).

lne reverse stoe

"uaio)

BASE

,

DIAGNOSIS
(i)

O/C

(il)

Voltage

(iii)

lntermittent

DIAG

NOSIS B
A spark in the
(i)

Dry

(ii)

Broken

(iii)

Faulty

DIAGNOSIS

(i)

Faulty lC1

DIAG NOSIS

(i)

Faulty

(ii)

Speaker frame

DIAGNOSIS
(i)

Faulty delay ine

two copper r ngs

(ll)

Faultv

DIAGNOSIS F
Faults of this nalure usualy
progressively

Dry

0
(1

On some early 63 s there may

)

under modlficatlons.
41l

e se

co

The loudspeaker should

reconnect lhe antenna
boards, at the coil
In

following

the

LED

an

of
Connect
side of the audio transformers.

lf

sparking

A

AC

supply fuse

selector in

AC

base

1oint.

connection.

audio transformer.

C

holding

between 1

supply

of the loudspeaker

T1

D

element.

resonances

E

coil. The faull may

between which the

element.

worsen resultlng n

nts

on audio or EHT clips.

1o

iailing

the lault may

board assembly.

be lnverted wilh

and d sconnect the

board end.

tests Ioudspeaker

connected

AC supply

is indicated

between

and

audio leads.

the fault

switch.

'on'

due to loose

pfove

T1

l OV

and 240V

generally

will

fittings.

be narrowed

spark is occurring.

difflcult to

the spark becom ng v

be discharges between

lsolated

be

shutdown

gate

Apply

lies

in the

ocate. The antenna being disconnected may cause the fau t to

as far as

audio and AC

red and white

may be identified

and

earth.

test 4

or 6

loudspeaker

be

an indication of the fault

down to one of two

Test 6 may

sib e.

the audio transformer shields and core straps, see 2b

the base. the spea[.er

either

supply leads disconnected. With the baseplate

w res wh ch run from the audio transformers

by a flattening

exercising extreme care to avoid

base.

coils, these beinq the

a so encourage the spark to become visible

producing

e ements or

of the oscilloscope

it.

more

contact

coi s whlch feed

with

trace

commonly the

removed.

to the coli

illumination

or

the secondary

the

5

OURD ESL-63

lf

sparklng is not indicated disconnect

1{a) and 1{c) under'service'. Disconnect

with the EHT and the red and white

Apply

AC suppy and audro. 1f

I

[aJ

DIAGNOSIS G
(i)
(ii)
(iii)

DIAGNOSIS H

(i)

i' I're

es

Vrl , T2,
R1

a.b.,

lf the AC supply volts are ow.

rc1. T1 , T2.

spedl,er ererre'lts or w.ng.

(where

R2

fitted).

a.b. - O/C, D11. D12.

sparking is lndicated

the audio

all

aud o transformer

particulary

service

and

of the black wires {rom the coil board. then refit the

on eary loudspeakers suspect

data

AC

supply. Remove the loudspeaker base as described in

wires re-soldered.

the fault lies in the coil board. if no sparking is indicated

T3.

speaker base

the

DIAGNOSIS I
(i)

Clips or wire

DIAGNOSIS J
(i)

No output, audio

DIAGNOSIS K
(i)

Speaker has been subjected to over
in some cases it may a so

DIAGNOSIS L
{il Faultv element.
(ii)

Resonances with n

DIAGNOSIS
(i)

Loose

dustcovers.

grliles

and cloth

(

Less commoniy a faultv

)

DIAGNOSIS N
(i) C ps
(ii)

DIAGNOSIS O
(i)

{ii)
DIAGNOSIS P

(i)

securng the wires to

Less

common y a

Neon

O/C.

R12

0/c.

Fault lies in EHT

value

resistor in

inks

M

joint.

dry

path

O/C.

be

the loudspeaker due

This

is recognisable

(see

service notes 2{a)(b))

bass element.

faulty

treble un t.

circuitry. In cases where

parallel

wth R13

for

oad

necessary

the ouvres may

to replace D11

to oose filtings.

by

a wrinkling

may be cured

EHT volts

and R14.

too ong. Replacement of these resistors

be oose.

are s lght y low, they can be increased by solder ng a similar

and

elfect of lhe dustcover materia and after

as described ln

Gentle tapping oJ these wil secure them.

2. TR1.

D1

(e)

on

page

should

14.

cure the fault though

hav ng removed

DIAGNOSIS
(i)

Faulty
identily the fau ty

10 disconnect it irom both

re-checking the leakage

DIAGNOSIS R
(i)

Faulty
leads. The faulty
disconnect t from both edges
one whlch sounds no dilferent whelher

N.B.

diaphragms.

DIAGNOSIS S
(1)

Faulty

DIAGNOSIS T

D scontinuous

0
MECHANICAL STABILITY

To improve the mechanca stabiiity

part

two
The two feet f
from leaning forward.

6

O

e ement

element due to O/'C EHT on one

lt is

e ement.

replacement

due

to excessive leakage

element. Alternatively EHT

edges of the diaphragm)

by means o1 the neon flicker

elemenl may be isolated by dlsconnecting

of the diaphragm) and

sometimes

In

tted

possible

such cases each eemenl will

EHT.

suspect broken link.

feet

are available and may

to the rear

for elements

ofeary oudspeakers

of the 63 baseplate

across the

element on

it is connected

which have no

diaphragm. D sconnect audio leads. Test 7 may help

shou d be

need to be

be ordered

shou d not be f tted with p ugs which wi

disconnected

working from

rate

each t

y.

This may be an O/C diaphragm. D sconnect

EHT from each element in turn

applying audio each lime.

to EHT or

EHT connected

physically

with cork

{fltted

4 x M12715A

as

Jrom

top

the

me.

not.

removed to isolate the faulty

feet)

each element in turn

loudspeaker

of the

The faulty

to

charge up

when used on thick spongey carpets.
and 4 x NDP'1

from

(remember

downwards and

(remembering

element will be the

adjacent

element.

'187.

prevent

the loudspeaker

to

ng

audio

to

testing

OURD

ESL-63

service

data

Complete testing
connecting

TEST

AF

Programme
Pre-Amplif

Power Amplifier
Tone Burst
Voltmeter

these unrts

EOU I PM
Signal

Generator

ier

E NT

Source

Generator

of an

-

ESL-63

as shown

with

may

S/C

-

see below

l

l

most

in Fiq

2.

protection

easily

be

carried

Ammeter
Oscilloscope

Reference
RF
EHT

out by using

Spark Generator

Meter

the

Loudspeaker

-

available

test equipment listed

from

O.uad Stock

IU[L] |

OO

ooo

l(,llr\l!11,4t

l'flf

'-I

No.

,/r-------\\

ET

OO

Si)1,,\

I

I

below and inter-

OEHTVMA

o

r

Fis.

I

I

I

l

^ I ^-

ffi

OC

ItSI

[:ii i,:]

2

Suggested

Test

lnstrument

Layout

for Complete Testr:ng

of ESL-03

(o) | (o)

op

loo

OURD

ESL-63 service

TONE BURST GENERATOR

y

When app

generator
loudspeaker.
circuil.

ng

Steady State nput signals 10 the loudspeaker

is used

to switch the output from

which may then

These

extreme cond tions wlli enable check ng

fau lts.

Fig.

3

shows a s

It is important

mple TBG

circuit where VR1

to ensure that the duty cyc e does not

the signal

be subjected to

data

these should not exceed 10V

generator

overload for lengthy

of the clamplng level and wi encourage any sparklng

controls the

exceed approximately 10%.

such that short bursts of s

pulse

repetition rate and VR2 controls the

periods

--iH

rms. The

gnal

tone burst

are applied to the

of tlme withoul damaging the clamp

pulse

duration.

..)J

T

1'oor

/

PULSE

ro'.

l-----'"

)G

s/NE

o

lM

FREE

RUN

-

VR2

2soK

220K

250K

t/R/

2v2

CAUTION
Extreme care should be exercised when

carrying out the following tests as contact

side of the audio transformers under signal

path

Contact w th the
from the AC supply voits. lf the nature
dscharged by short circulting

EHT

shou d be avoided both when

of the test be ng carried

polnt

A

(Flg.

5)

to

conditions can be fatal.

loudspeaker

the

necessitates contact the EHT shoulo

out

earth.

with AC

supply

vots

s connected

disconnected.

with

the secondary

to or recent V d sconnected

In

each of the

tests the oudspeaker s taken to be standng uprlght ln ts competed form un ess othervr'ise stated.

1. IMPEDANCE
EOUIPMENT CONTROLS

Signal Generator

:

TBG :

Pre-amp

lncrease
several

the

frequences

volume

the

on the

pre-amplif

impedance

devlations from this curve indicale a fault

1 kHz
Sine Waves
Free

Run

-

Input
Volume

er to

TBG

-

Tero

a comfortable lsten ng

may be calcuated

n the aud o circuitry.

Ammeter
Voltmeter
S1

level. By

and compared to

:
: o-1

: LlC

voltage and current

taking

the mpedance rnoduus in

f rst

be

fo

owlng

0-3O0mA

0V

read ngs

Fg.4. Large

at

Fig.4

l,l l

r L L 1 '

+,

lever-

i/*-

oeeeruoarur

I

l

l l'li

rii

i

i

+

I-

l
r-

I

t

t

I

I

1

I

\

tr+1

/

\l

\'l

\

\i

\

\

-\-

I I

i+

1

l*

T

I'

T

llirrrl

IMPEDANCE

Tl-

MODULUS

I

T

\

t

I

I

J

\

N

1*'+

>-\*

j

I

Hz

ir

1K

IT

OURD

ESL-63

TONE BURST GENERATOR
When

applying

generatot

Sleady State input

is used to switch

signals to the oudspeaker

the output from

oudspeaker. which may then be subjected

circu t. These extreme conditions wi

enab e checking of the

TAU ITS.

Fig.

3 shows a simp e TBG circult where VR1

It s mpodant to

ensure

that the

duty cycle does not

service

the signal

data

generator

to over oad for

controls the

exceed approximate

4066:

these should

such

engthy

periods

c amping

pu

se repetit on rate and VR2 controls the

I

gt,

not

exceed

that short bursts of signal are app

time without damaging the clamp

of

evel and w ll enco!rrage any sparking

T

0%.

V

1OV rms. The tone burst

ied

to the

pu

se duration.

220K

2saK

lR/

2y?

CAUTION

Extreme care should be exercised when carrying

out the
side of the audio translormers under signal conditions
Contact

wlth the EHT

from the AC supply volts. lf the nature

discharged by short circuiting

tests the oudspeaker

path

should

be avoided both when the loudspeaker is connected to or

of the test being carred out necessitates contact the

point

A

ls

taken to be standing upright in lts completed form uness otherv,/ se stated.

5) to ear1h. with AC

{Fig.

1. IMPEDANCE
EOUIPMENT CONTROLS

Signal Generator
TBG

: lkHz
:

Sine Waves

Free Run

-

Pre-amp

increase

several

frequences

the

volume

the

on the

impedance

:

pre-amplifler

deviations from this curve indicate a fault

20

tl

t r r,l

J

/\

uevrl

7

oepervoarur

I

+

lnput
Volume

TBG

-

Zero

to a comfortable lsten ng level. By taking voltage and

may be calculated

n the aud o circuitrv.

i

\

tr-*l

r'

\

tal

-\

+--'-t.

\

I

\.

and compared

\

j/a

_l

.---'1

/

'

VR2

250 K

rrln

'i""-,,*

'i'

'l

F---"

Ito

- | /

-HO/M

PULSf

FREE

RUN

POVER

s/NE

SUPPLY

za,

-

.-_

2l

]VA

following tests as contact with the secondary

can be

fatal.

supply

Ammeter
Voltmeter

S1

recentlv

El-lT shoL,rd

oisconnected

iirst

vots disconnected. In each of the

: 0-3O0mA
: o-1
t t/c

fo

current read ngs at

to the lmpedance

modu

in Fg. 4. Large

us

1f

ft

1r

11

lLrl

IMPEDANCE

MODULUS

I

be

owing

0V

Ftg.

=l

I

l

_ll

li

ll

I

f

ill,1

4

100

Hz

service

data

the baseplate

kV.

ET]T VOLTS

2.
AC supply and audio leads
(a)

The loudspeaker
should be

(b)

AC

supply volts

Measure

the volts across the

should be inverted

removed

and the baseplate lifted

should now

disconnected

and

be connected.

points

labelled A

OURD

stood on a

out.

and

ESL-63

firm,

clean surface.

B in Fiq.5 which should be between 5 and 5.3

The twelve

screws securing

\

Fig

5

3. CLAMP

Signal Generator

TBG

Pre-Amp

Ammeter

S1
Oscilloscope
Audio leads

CAUTION

Extreme care should be exercisad when

CIRCUIT

and Voltmeter

disconnected

5OHz

Pulsed
Sine Waves
Volume

-

Input

Disconnected

LlC
Sensitivity

from loudspeaker

carrying out the following test as contact
side of the audio transformer under signal
(a)
(b)

Follow

To

check

instructions

thal the

under Test 2

clamp circuit is functioning correctly.

(a).

of the oscl loscope.

Connect the oudspeaker audio leads. lncrease

{c)

the oscilloscope.

For

loudspeakers with variable

early

Ät

approximately ZS0 to Zg0 ciipping

clamping leve s lt ls

4. RESONANCE CHECKS

EOUIPMENT

Signal
TBG

Pre-Amp

CONTROLS

Generator

Hz

5O

Free Run

Waves

Sine

Volume - Zero

Input - TBG

Ammeter
Voltmeter

s1

Oscilloscope

Disconnected

0 to 1OV

LlC
Disconnected

-

Zero

TBG

1OV/cm

conditions can be

polnts

the voJume on the

should occur
advisable that modilicatlons 1(a)

with

the secondary

fatal.

D Fig. 5 should be connected to the input

C and

pre-amp

wh st observing the transient trace on

indicaling that the signal is crampeo.

be carried out.

(a)

Increase

the volume until

the
The loudspeaker response shou d be
where dlaphragm resonance occurs.

voltmeter reads

pure

and free from rattles at

8V

rms.

Gradualy

sweep up and down the

frequency range.

al frequencies except at approxlmately

50 Hz

OURD

5. SPARK DETECTOR CIRCUIT
EOUIPMENT CONTROLS

Pre-Amp : Volume - normal listening

Ammeter and
51 : L/C
Oscilloscope : Disconnected

ESL-

Voltmeter : Disconnected

63 service

-

Input

programme

data

source

level

Generate an

{a)

ighter. The loudspeaker shou d

recognlsabe by ts

6. SPARKING

EOUIPMENT CONTROLS

TBG : Pulsed

Pre-Amp : Volume- Zero

Ammerer and vottmeter . $:::";:::.
S1 :UC
Oscilloscope

(a)

Increase the volume to a bearable level

shutdown,

most likely under these exlreme cond tions.

frequencies above

At

transient

The

7. LEAKAG
Disconnect

Rf

spark c ose to the base

quietnng

indcating the

waveform trace will

E

the audio

leads

of the loudspeaker. This may

shutdown for 4 to

effect and whi

:

Sine Waves

: loV/cm

presence

T 2 klz where shutdown may be difficu t to dentify the oscil oscope should be

trom

the oudspeaker.

and sweep up and down the

of a spark. Sparkng is

decrease

be created using an electronic

5 seconds

st audlo mäy sti lbe heard it wi

in

amDlitude if shutdown occurs.

The loudspeaker

(T

second on very eary loudspeakers).

frequency range iistening for loudspeaker

general y

as a result of

shou d be si ent.

mulfled

be

insulaton

cigarette

Shutdown is

and distorted.

breakdown

observed.

vJhich

is

PROGRAMME

8.
EOUIPMENT

Pre-Amp

Ammeter

and

s1

Oscilloscope

(a)

By switching
lou dspea

ker.

CONTROLS

Voltmeter

between R/C and

Volume - normal listening

-

Input
Disconnected
R/C
Disconnected

L/C listen for

programme

L/C

and

any differences between

source

level

the 63

under test and

the reference

10

SCTVlCC

Service

1. LOUDSPEAKER
Disconnect
(a)

of the

Ouad

ESL-63 is relativelv

audio and

Removing the base
transformers and the nuts

BASE

AC

plate

supply

(12

screws)

securinc

st;aiqht

volts.

the loudsoeaker

forward

Discharge

gives

access

OURD ESL-63

the

once

EHT.

input

to the

and delav

fault has been

protection

lrnes to the base.

diaqnosed.

circuits,

EHT

power

service

supply,

data

audio

(b)

The

removed
stra ig htf

Frg
chassis

sub

by undoing

orwa rd.

6

holding

AUDIO

TRANSFORMER

L1

the

5

protection

the

four

screws. Replacement

S U PPLY

TRANSFORMER

circuits,

EHT

AC. BOARD

CLAMP/DETECTOR

ANT

c{Pl9ISn

BOAR D

power

EHT

of the

BOARD

EN NA

ccrL bonnr

supply,

protection

A.U

TRANSFORM

input

and

circuit

and

DIO

ER

414

AC

connectors and

power

EHT

fuse

supply

can be

is then

quite

(c) To remove the

transformers
antenna and

(red
undo the

Fis.

7

entire base of the

and white wires),

nuts. The

eight

loudspeaker

and the EHT

base may

it

rs

sinrply
supply
then be

necessary

(orange

lifted

wire) and

off.

to

unsolder

to unthread

the feed from

protection

the

both auoro

circuil

11

OURD

ESL-

63

service

data

2. REPLACING
Disconnect

(a)

Remove
cloth

audio

wooden

the

from the

AN

ELEMENT

and AC supply volts. Discharge EHT.

lrom

top

vecro

hooks as shown in

the loudspeaker

Fig.

8,

by sliding

and

lt

to the

pul

the cloth down takng care not to Iädder

righl

(viewed

from

the front). Detach

it.

the

grille

(b)

The
prise

handlrng the

Fig

griiles

froni and

the

8

are taped top

bac<

grilles

as

it

arti bottonr

griiles

from

their

is relatively

easy to

prevent

to

retaininq

rattles

slots

distort

ihe

ancj

once the taoe has

rrr

the

sicle extrusion.

edges

oeyond

repair.

renro\ert

beer-

Care shou ci

raker.

be

i

s

r-,ossible

,,r'lren

to

1a

IL

Fis. 9

(c)

The

dust cover is fitted
gent

and

y

lifting

to a clip-on frame

a corner free.

OURD

and is removed

lnserting

by

ESL- 63 service

a screwdriver at

either of the top corners

data

l0

Fis

The

screwdriver is

other three corners

then

slid down

after which

betra",een

the dust

dust

cover

cover

and side

can

then be witbdrawn.

frame.

This

should be repeareo In

A

M

each

of the

Great care should be
necessary

from

away

replace

to

the working

11

Fig

taken as the dust

plastic

the

area so

film

as described in'3.

to

as

cover is fragile.

avoid

being damaged

lf

the dust cover

removed

When

by solder splashes

does become ruptured

the

dust covers

or wire

should

cuttings.

it wilr

placed

be

oe

well

4a

IJ

OURD ESL-63

service

data

Having removed

{d)

remove its four fixing

from the electrode.

On eary oudspeakers these clips had

elements there is no tag

be necessary to make up

ower elements additional items

(i)

In

the case of the top

In the case of the lower

{i)

nor ng rne r sequence.

(

i)

The bottom e
therefore frst

For loudspeakers
(e)

With
covers are In

may nol

should

the

be

fau

be

both dust covers il

screws.

and a wire link

some wire links

element remove

ement cannot
be removed. The

after serial number

ty e ement rep aced

place

thev must

hot

enough but restricting

kept

moving a the time n

middle

s necessary

Care must

will need

be

the loudspeaker

be retensiored

be taken not

a

tag to which

is

soldered direct
when rep
to be removed

a

element

removed
bottom

1 16O0

the delay line

element

the a r f

order to

so the top

w th the lower

see modilications

to unso

can then

wth a hot

ow by hand will raise

prevent

der the e ectrica

to overheat the c

the soldered connection

to the body of the clip. n

acing elements. For removal

first.

plate

(8

screws).

eads wil have to

middle e ement n

\,\/ill

then need to

(5).

be re-assemb ed in reverse

air b ower to remove

burninq a hole

co|)nectors to the fau tV

ps

as thev mav become

was made.

some cases it mav

of the top

be unclipped from the louvre,

The lower mtoo

olace.

liftecl

be

the temperature

in the mater a .

about i 5 mm

orcler. Once the

all wrinkles. A

sufllcientlv.

elernent and

ufso oerecr

On currenr

element and the

to ctear tTre base.

domesllc hair

prooucrion

e musr

dust

The

blower

therefore

two

first

dryer

12

lie

3. REPAIRING
Disconneit audio and AC
It

f rst

wl I
(a)
(b)

14

be necessary to obtaln a dust

The

damaged dust cover shou d first
Strlp the
tape to the frame. Spread the materia
sma I

Enough mylar is supplied tor
never scissors or a knife.
Remove the
and
Clip the dust cover frame

old

pieces

press

,fuh*

A OAMAGED DUST

supply volts. Discharge

materia

of stickv

protect

down. Tr m the edges with

and double slded
tape so that the materia

two attempts

paper

ve

from

on to the loudspeaker

COVER

EHT.

repa

cover

be removed from

sticky tape from the frame. Appy

out on a

the doube

a hot knife

r k t which mav

the oudspeaker assembly as described in 2(a)

smooth cean surface. Secure the four corners and sdes wth

s smooth

so the sheet should be cut in

sided tape. carefu

or soldering iron.

and remove a wrinkles

free from wrinkles.

and

be ordered as stock number

repacement

place

y

the

using a hot knife

two

the dust cover frame on

descr bed in

as

doub e sided stcky

the atter

063DCPA.

(b) (c).

or so dering iron,

the materia

pan

of 21e).

OURD ESL-63 service

data

4. REPLACING G R ILLE
Disconnect

It will flrst be necessary to
on oudspe€kers manufactured
rnanulaetured

8nd replace two

order
(a)

Fol

audio and AC supply

pnor

to ths

ow nstructions 2(a). 1(a)

CLOTH

obtain a repa r c oth krt \^'h

after September

date

gr

e c oths in order to

volts. Discharge

v/hich is

and

no\r,, obsolete. For

1(c)

resper:ti'ey.

198T

rna

nt.l n

EHT.

may

ch

ghty

s sl

tlre earlier

nlatcfr ng

be order."d as slock

ditterelrt to the cotlr used orr ou'lslreakcr,;

loudsl)eakers t v'

pa

rs.

fltr

f

nurnbef EC31a2A. The

tlrerelorc be

J*

"s"

il

Becessar,/

c oth üsed

to

Fig. 13

(b)

Lifl off the wooden
assembly
w th creases down the middle
ladder the materia. Fix
ends.
pattern

(c)

Ensure that
loudspeaker.

(d)

Staning at the middle of each s de
but not to risk laddering

€venness ol stretch. l\,4 itre

and

Fold to form

and adjust lf necessarV.

the wooden base trim is free from

base. Disengage

remove.

Refit the base

Slip the new

the cloth to lhe velcro fix

pleats

mitre

or teäring, and fix

the exist ng c oth from the ve cro J xings

cloth ovcr the nverted

of the sides. A

the

at

corners and

and baseplate

and work ng

pleat

the corners

gn

the

ngs starting

attach to the

dust

and

nve(

and

to velcro. Trim

as before and iix the ends to the ve

the loudspeaker.

to the ends, lft the c oth stretch ng

oudspeaker eav

palt-.rn

w th the coflrers, aiways taking

at

refit $i ith

surplus

off

the

centre of each side and working out

velcro

at the ends. Recheck the a

the handle recesses away

c oth and check

at the bottcnr of the oudspeaker

ng

about 2"

cro.

prolecting

great

from

it

sufficient
for

alignment and

Refit

the wooden top.

care
gnment

the

to

V

above

not to

to the

make

t

of the

t trght

^-

tc

OUCD

ESL-63 service

modifications

data

ORIGINAL

Coil
Caoacitor
Clamp/DetectorBoard

EHT Board M12525-2
Neon Board M 12582-

Pre- seria number 1O,OOO ioudspeakers

1. JULY 1981
(a)

R10, Tr2. Vr1 , D2

added.
the c rcuit d agram SS 2 and may
some cases

(b)

R19 changed from 1M to 10M.

approximate y 4 seconds.

(c)

D11. D12 changed

AUGUST 1981

2.
(a)

Capacitor board
the need

(b)

Audio
gr

sparking occurring between

(c)

C13 a.b.c.d changed from 22OpF

ISSUE BOARDS

Board

Board M 12538-2

This fixes the c

D15 s made

M 12538-2

for

the series resistors used

transformer shrouds are no onger

es v a the audio transformer shrouds, now

M12524-6
M12418-7

1
w corre ate to mod ficat

anci RT 1 removed from

amping

from

leve

. When carrying

be accomrnodated

from

up

S920 to 1N4003.

2 T 2V zeners

Stock No. R10M0J1. Th

changed back to

on

the shroud and the transformer

lo 33OpF

bV the r

ons

the clamp/detector board. D15,

out this modif cation DT 5 should

us ng the vacated holes marked

and either a link or an ordinary diode.

s increases loudspeaker

Stock Number D1N4003.

pre-re

the

M12538-2

earthed. Earthing connections which

run direct from

Stock Number

ease version, M12538-1.

no longer

exists.

subchassis

the

core strap.

C330PKP.

approximate date of manufäcture.

24V Zener Stock No. D4824VA

be connecreo as snown In

as E and

shutdown time to

ng improved

Us

prevousy

gril

to the

ran from subchassis

es. This

F ln

Fig. 14. In

capac tors

overcomes

to

3. SEPTEMBER 1981
Louvre soldered clips changed

from adjacent louvres.

4. APRTL 1982
(a)

Loudspeaker frame mod

(b)

EHT board 1112525-2
soldered and situated on the
(i)

C1 6. C17

(ii)

C18 C23 change

(c)

Clamp/Detector board changes to ISS

R21 100O Stock No. R100RJ1

ii)

5. SERIAL
Loudspeakers are now titted with modlfied

push

a

When

centre
needed. The
reinforce the

Top and bottom

fit nto tapered s ots.

rep acing a black upper

elements to

change from

NUMBER 11601

maintain

leads

shou d be

flxing.

units are

to short necked type

fied ln order to

changes to M12525-3 for

printed

2On to 1On Srock No.

from

20n to two 10n

or ower m dd

the

balance between

pushed

completely interchangeable.

sde ofthe board M12582-1,

9 for

added.

into

the ouvre

Stock No. FC2489A. W re links aTe now used to connect clips

ower dust cover resonance.

production

C1ONOZT.

capacitors connected ln

producton

white ouvres. Deay ine eads are no longer

e element by one with white louvres it

them. The c lps used for flxing the delay line

slots and

purposes.

purposes.

have a

small amount of cornp lant

Consequenl with this the neon s now

and the

neon

paralle.

Stock

board orentation changes.

clipped to the ouvre but are

s adv sable to

No.

C10N0ZT.

eads

replace both these

r,v

il no onger be

glue

added to

COMPON

D3 Dl 0.
D11, D12,

rR1,2N6489,8D910.
TR3. E5270.

T1. T28O0B. Selected va ues oI f1C226B

12. 2N4992, 2N4993, 2N4991.

16

ENT ALTERNATIVES

1 4V30.
1N4003. 15920

'1JK30.

BD 744

8C184. BC41

3C.

mav be used

D

BS08A.

but shou d

may be

used if they

be avo ded.

are of

tvpe nLrnrber \''109 7

clampfdetector

OURD

ESL-

63

service

data

M12418

-

tSS

7

To R 151C25-

To

D13---,--]

6----_---

To

L'l

-_ll'l

| I

rrll

ooco

l^,;1Dr4 \J

-rI

'T

-ri-

rE

tgilP 'l'

I äA^ | -

r"t.z\Jt

I

r r<T l

-)-l

(-

I*T' I L

a+nicd}-D{=-e+T

l-l

t-l J .r-

i/

D'6

ccoo

I r

_LB

#F'F$

zto

rR3

i + l:l

i cze

t_Bt_;l

'

"to

o"^lll

c,tLA

Ct+i

z

'

NiTlgiäi;f-

-t

-L

-'=/

|

5

\i-l?

-r

|

rDl

lfrvL,

tl

rtt

rvnr

ra

+

^

i-rll-

-

[--

oo

fRt--l

xzu

r

;#p't

1-tlll--.r-

--+<---

- 82- -

in'

r

-

To SK2

To 115

f

---L

---F

M12418

-

lss

Fig.

14

10

9,

R 151C25

To

To D13

To

116

=-l

tll

blJ-+ 1

I+TT

ooo

rü:t

I lD14

l+-l

I

r---r [11

t',TF

@h,.

Lc,77 | i''

I

D16

ANTENNA

TO

o

ocoo

t J lRTl F-zl

Dlr

,or

lF

I

1-1
l-l?'

l^,lO1

l!

l+r

--<p-

-{F-

c1t,

I -

g3-.=r

eh

p_;j

I

rq-A"

,

T1

r--,

-IR1B

-I

cCFf.$

^

TRi

F

R16F

T2

Q

i

i=rll

i

I

cza

co

t+l

--

TRl

Hl

x i--

To

SK2

To

L1

5

To

L14

-

Fis

15

TO ANTENNA

17

OURD

eht

M12525

-

tSS

ESL-63

2

to

EHT

Loudspeaker

Diaphragms

I

service

data

M12525

-

lss 3

c16

+*+*

Tr',-r

--{t.-

-ät-..-

D7

tl

*-

YA

ll

DB

--{k--

c??

D9

I

J,

+

f

+

t

I

I

D10

--{t--

C?3

l,l,

-rll

lel l:l

l*l läl

T

l=l

--+

rl

l-l -j-

tEt | |

le I l*l

++

To 116

to

EHT

pea

Lo u ds

Diaphragms

ker

To Neon

D6D5D/rD5i

PCB

i

C16 C17

C1BqC19qC19b

/\_t rlÄY-tfäYÄYÄY

l-.---

/\ \/ /\ \/

i+

trl

rf

?

t

'

,,,

---.-rf,

tl).Li-\

?t

ol

----_r

o,'o

i\r\

C??q

C21o

C20q

C20b

C21b

Cl?b

C23o

C23b

ÄYÄr-rt-arÄrÄYÄYÄY

,lf

_-

i

F

E

ü

lEl

?

1B

coil

OURD

ESL-63

service

data

M12524 - rSS

_o

CD

C)

o

F

6

O)

{}-

:

ü {t--

8U

/U

.C

ca

L

c)
o
o
o

O

c)

l

-

ü

l-l

l-l

-l-

i

I

r

___)

o

F

U)

E

cU

o

CO

o

.t

c)
(U

O

CU

O

o

F

fi

ll

l-l

l*l

It
il

1-

o'tll

I

(-ll

)tl

a\

a-\

r--J -,/-Y-\

(-l'

a\

rn --l-V-\

c)

€

c

c)

+C

cc)

6c)

-C

L]I

<D

af.

c->c)
C+

oo
o^.

-v

.,34

.\ C

F.F

C)

.C

ca

L

c)
O

O

o

O

c)
C
C

an

Fig 1B

19

OURD

ESL-63

service

data

components

list

CLAMP BOARD ASSEMBLY

Part No. Doscription
C10N0JS
ClKoUZE Capaciior 1000/u
C]U50KS
C330NJM Capacitor
D2N64B9 Transslor
DAAT 19X Diode AAl 19
DBSOBAA
D2N4992
DBY225X Brdge Rectfer
DE5270X Transistor E5270
DT N4003 D ode D1 N4003
DNE555P Timer NE555P
DNF231A Melal HS Washer
DT2B00B TFIAC T28008

I1C226B

DIAGg2A TRIAC TAGS2A.3
DVN/ T BXX Br

Capactor TOI)F 5 160V

Capacirof 1.59.F 10 100V

330nF 5 352 48334
2N 6489

D AC BS0BA,01
DIAC 2N4992

AY225-1AA

Rect f

dqe

VN./l1B

er

832561

16V

EK

sze Ia22O

832562

E.H.T. BOARD ASSEMBLY

Part No. Description
8N1630S
C20N0ZB Capaciror 20nF HD25
C47N0JS Capacilor 47nF 5 250V 832561
D1AV30X Dode 14V30
1125254 EHT PCB M12525 lSS2
l125B2A Neon PCB MT25B2 lSSi
P41,44072 F Tags

Neon

K3 20N0ZS

Circuit Ref. Part No. Desc.iption
C26
C2B
C14
C21

TRl

D16
12
12

Dt
TR3

D11

D12 R3F30JC Resisror

.

C1

T1

T3

D14

Circuit Ref.

Nl
C16 C23
C1

5 R220KJA

D3 DlO

DZTSVAA Zener Diode BZYBBCT5V
FET2TOA Eye

1241AC
LSC1OOT
NHSTVsA Heatsink TVs
RlOOR.ll Resistor
RtoKoJl Resistor tOK
R120RJA
RjMooJt Resistor 1N/t
R2K2OJ1 Resisror 2K2

R6B0FJ1 Resisror
TN/]3OBPA
TN/]3FHPA Nut M3 Fu Hex
D4B24V A Zener
FTOMOJT FesSIor 1OM

Pan

No. Description
R10N./0JA
R1SoKJA Restsror TBOK

RI298ZZ

C10N0ZT Capaciror 1On{

12525A EHT

LS]21O

et

pCB

EL63

Choke RF tmH SC1O

1OO 5 O5O

Resistor 120

3.3 ohm 5 TVpe TFP6V
680 b 050 R1i

Screw M3 Bmm Suo.

Diode 24V bW

Resslor i

Resislor 220K

Voltage Dependenl Resislor

0t\,4 5 UpN/tOZb R12

pCB

N/112525

N/ted. Brass

(Camo)

5 050
b O7b R1B

b ObO

b O5O

ST BZp

5 o5O

5 O7b
b 075 R13.

2A +5Ot" 2KV

ye

t12418 SStO

pan

tSS 3

o\^.

ST. BZp

Ref.

Circuit

D2

Lt3

RS. R21
R2O

Rig
RT 6
Rj

R2a.b.

a.b.

Dlb
R19

Circuit Ref.

Ft3, RT4

RT 4

VDR].

VDR2

C16,

C1j

CTB C23-a.b.

CAPACITOR BOARD

Part No. Description
C10P0KB Caoacitor TopF 10 HD25CG10P0KS
C22P0KB Capacilor 22pF 10 HD25UJ22P0KS
R4K70JT Resislor 4K7 5

l12538B

COIL

Part No. Description
1125244
R1

501(l(O

R360|(JC

Capacitor

BOARD ASSEMBLY

PCB

EL63
Resistor 1
Resistor

PCB

MT253B SS2

(Coil)

10

50K

360K 5

050

lt/1

IF1 169

TFl

M12542

lSSo

2542

1

69

FRAME ASSEMBLY

Part No. Description
EVEL1 2A
FT2006A
FU2945A
IFVP'IZA Vtoplast
IFVP3AA
\P47O1B
M12462A
M124658 Slde Frame

l,/t1247
M 1 2 5034 Bottom Frame
N/ 1 2

5044

Cloth Securing Strip
Shakeproof Terminals
Spire

Clip

VLtoplast Strrp
Se

Dust

0A Keyhole Plate

Top

Strip12mm x 10mm

lotape

B ack

Cover Securing Plastrc

(BO9mm)

Frame

3mm x l

Omm

Extrusion

Circuit Ref.

C11, C12
CT C10
Useon lssue
2 Board on

Circuit Ref.

R3a.b.

R5,

RB

y

R4a.b.

R6, R7,

Part No. Description
PAtVt4072 F Tags

T2b3BA
C22?OXX Ca)aclar
CT 0P0XX

Part No. Description

C330PKP

L63C01A Delay Line

Part No.
N/1 2b4gA

1V12599A
TC4OBPA
TC61sCA
TC620CA Drive
TDN/4SPA Washer
TM445PA
TN/4Fi]PA Nur
ZTCAUAA Sellotape 1 rn

M127 13A

M127

Caoacror

Capac tor

Capacitor 330p 6KV

Description
Griile Spring
Suooorr Rail
Drive
Drive

Screw

Side Ra ts

12A

Rubber

pCB

22^F

10nF

Coi

44

Screw
Screw 64 15mm
Screw

64 2Omm Sup Csk.

M4 I ST.

M4 45mm

M4 Futt llex

Inserrs

t\,4T2538 SSI

79Omm

Brnm Sup Pan.

Sup Csk.

BZP

Pan

Sup.

ST. BZP

Clear

Circuit Rof.

Use on SS l

Board

Circuit Ref.
C'T3 a,b,c,d

L1-L12

ST. BZp

20

,.

OURD

ESL- 63

service

data

BASE ASSEMBLY

Part No. Description

AFRA61A Cork Feel M125074 Eanh Bracket

-

FC70490 Wre SecLrrng
FF35010 Push on Fix M12547A

Clip TN4406PA Screw

FTB6469 SoLderlag 684 Brass Hot Tlnned 1123954 Audio Transiormer
L4T 24694 BasepLate MT 24684 Audio Translormer

Part No. Description Circuit Re{.

M4 6r..n

Sup. Pan ST.

BZP

Base Moulding

L'14, 115

Shroud

">*

SUB.CHASSIS

No. Description

Part
BL5053R

C22OUKE

FCC200X LED Holder
FT1757 B Black Input Term nal
FT1 7

R Red Input Terminal

57
FTBOSS5
lG375BA
PF3961A Fuseholder
PPP579A Plug
R1 R50JC Resistor 1 .5

S630FFA

DUST COVER

Part No. Description Part No. Description
EFN/YO2A
lP5474A f ape 5474
1A124644 63

M ISCELLAN EOUS

Part No. Description
EA402AA Exp.
IFVPOAA Sponge Strip
M1245BA Base
M12459A Top Trrm

TC620PA Drive Screw
ICL\22P4 Drive Screw
TCBI2FA
TCB12PA Screw,
Tl'/306P4 Screw M3

FF13060 LoLrvre Push

ASSEMBLY

LED XC5053R

Capacitor 22OpF

Soldertag 6BA
Grommet

3

AC

Supply

Red

C200

pin

AC Eur. lnput

ohm 5

Switch

ASSEMBLY

Mylar 2.51u

650mm
Black 1rrlm

Dust

Cover Suooort 600nrm

COMPON

Alum.

650 LWM

6mnr

Trim

2Ornrn

64

t/a"

Drive

6A

Screw BA 12mnr

Selftap NoB 12rnnr

6mrn Sup. Pan

On F x

20 50V non-pol

C25

SK2
SK1

D13

-

Panel

R15
S1

Wrde

x 25nrnr M124BBA

ENTS

x 805 SWlv4

x 1Orrnr

Pal

Sulr

Sup Pan

Cl

Sup.

ps

Flarcre

Par.

ST BZP

SV71 085
TD86NLF
TtV306PA
TM30BCA
IM330PA
TN/3FHPA Nut M3 Full Hex
TM406PA
UMA1ODA
1,412467 A
L123944 AC Supplv Transformer

M124648 63

Part No. Description

FTB4ss5
tP.1070A Foilex Mera Tape
TN/3gBCA
TN/330PA
TN/3FHPA Nur M3 Fuil Hex.
FC24B9A Louvre
TC4OBPA
M12532A Insulator
M12522A
IFVP3AA

Voltage Selector
Washer Shakeproof 6BA

M3

Screw

Screw M3

M3

Screw

M4

Screw
Fuse 2Omm
Chassis

Dust

Cover Support

Dust Cover Bracket

63

Soldertag

Screw M3
Screw M3 3Orrm Sup.

Soldered Clrps

Drive Scre,"v 44

Coil
Sponge Strip

PVC

Holder PVC

6mm Sup.

Sup.

Bmm
3Omm Sup.

6mm Sup.

'lOOmA

4 B A

Bmm Sup.

Bmm Sup

(Bottom)

350mm

x 10mm

3rnnr

Pan.
Csk.

Pan.

Pan.

Delay

/BOmm

Csk.

pan.

585mm

Circuit Ref.

Ll 6

pan

\*

COMPLETE SUB-ASSEMBLIES

Part No. Description

BS 1 A Base Assembly

063
()63CA1A

()63CH1A
{)63CL1A

063C01A

C63CV1A Dust Cover Assernbly

DEl A Dclay Line Assernb

O63

FR 1 A Frame Assernbly

C63

Capacitor Board Assenrbly
Chassis Assernbly
Clamp Board Assemb
Corl Board Assenrb

y

y

y

Part No. Description
063HT1A

LA1 A Audio Transformer

063
063ELN/A Lower Middle Element Assembly
063ETBA
063 EUMA Upper Mrddle Elemcnt Assernbly
PSP5BBA Angled
063NE1A Neon Assemby
O63DCPA

E H T

Board Assembly

Assemb

Top

and Bottom E

AC Supply Socket

Dust cover Repair Kit

ement

y

Assembires

21